buy a mac. sound like a shit advice, but I heard it for many years. bought one 1 month ago. its simply impossible to make such things on PC. I use crazy software chains like Provessing > Syphon > Resolume > MadMapper and it works like magic!

Keystone is available for installation through the Library Manager, and I was able to run the examples in mappingtools that don't require GLGraphics in Processing 2.1. SurfaceMapper is 1.5 only as it was mentioned, since it seems to be entirely based on GLGraphics.

Just as a quick note, there seems to be a project that is (or was) attempting to bring Syphon-like functionality to Windows, it is called Wyphon.

Very interesting question. Maybe slightly irrelevant to this post, but it would also be interesting to be able to map a 3d view of the geometry in processing to a projector and work directly with 3d. Any info on that would be greatly appreciated.